WSEAS Transactions on
Power Systems

2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | Pre-2008

Print ISSN: 1790-5060
E-ISSN: 2224-350X

Volume 11, 2016

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of WSEAS Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

Volume 11, 2016

Title of the Paper: Unified Power Quality Conditioner: The Indirect Matrix Converter Solution

Authors: M. P. Alves, T. Geury, S. F. Pinto

Abstract: Power Quality (PQ) parameters such as voltage RMS value, Total Harmonic Distortion (THD), and Power Factor (PF) are main topics to be considered in the connection of sensitive loads to the grid. In this paper, a Unified Power Quality Conditioner (UPQC) based on an Indirect Matrix Converter (IMC) is proposed to address some PQ issues as mitigation of voltage harmonics and compensation of sags and swells when supplying a sensitive load. Also, it allows the mitigation of grid current harmonics in the Point of Common Coupling (PCC). The control of the converter is performed using the sliding mode control method, associated to the state-space vector representation, allowing fast response times to disturbances in the grid. The whole system is tested in MATLAB Simulink software, and the obtained results show that it guarantees PQ improvement in the PCC.

Keywords: Power Quality, Unified Power Quality Conditioner, Indirect Matrix Converter, Sliding Mode Control

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #28, pp. 244-250

Title of the Paper: Contribution of Integration the TCSC Device and Wind Farms on Power System

Authors: Adjoudj Labiba, Lakdja Fatiha, Gherbi Fatima Zohra

Abstract: Generation of electricity from wind power has received considerable attention and integration of wind farms based on double fed induction generators (DFIG) may have significant impacts on power system operation. This paper analyzes and compares the integrating of wind farm and Flexible AC Transmission System devices (FACTS) and their impact on IEEE-9 bus and IEEE-30 bus test systems. The west-Algerian network (2012) is also selected for study and different cases have been simulated in MATLAB based Power System Analysis Toolbox. Therefore, we must choose among FACTS devices, those with specific applications such as controlling the power flow, Thyristor-controlled series compensator (TCSC) is the best choice for a proper control of power flow and consequently the reduction of active and reactive power losses. The simulation results show clearly the effect of wind farm and TCSC device on power quality of electric power system.

Keywords: Power System, TCSC, wind power generation, DFIG, power flow analysis, Power System Analysis Toolbox

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #27, pp. 232-243

Title of the Paper: Analog Filter Design for Harmonic Reduction in Wind Energy Conversion System

Authors: Vikas Kumar Sharma, Lata Gidwani

Abstract: These days Harmonics is major Power Quality concern for the Power system engineers. The multi-component, complex and dynamic power system has serious issues of harmonics which makes system nonlinear. The harmonics in the wind energy conversion system is mainly caused by non-liner loading effect from the power electronics converters and non-liner load. This paper presents an efficient analog filter combination for harmonic reduction of a grid integrated wind energy conversion system using Permanent Magnet Synchronous Generator (PMSG). The main purpose of the analog filter combination is to reduce Total Harmonic Distortion (THD) at different buses. Various combinations are taken using different analog filters and designing methods. These combinations are used at 575V, 25 KV, 120 KV buses and results are taken during normal as well as faulty conditions. The results are analysed for different faults at 575V bus and best combinations are suggested 575V, 25 KV, 120 KV buses.

Keywords: Wind Energy Conversion System, analog filter, harmonic reduction, Total Harmonic Reduction (THD), Permanent Magnet Synchronous Generator (PMSG)

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #26, pp. 220-231

Title of the Paper: Geometric Modelling of Low Concentrating Photovoltaic System

Authors: Ionel Laurentiu Alboteanu

Abstract: The paper presents aspect to increasing energy production of photovoltaic systems by concentrating solar radiation and orientation of photovoltaic modules. To focus sunlight on photovoltaic surface and increasing thus the energy absorbed, the concentration solar photovoltaic systems used either optical elements retractable (usually Fresnel lens) or reflective elements (usually mirrors). The photovoltaic concentrating system aims to reduce expenses regarding photovoltaic surface and replace it with optical materials. Geometric design issues are presented for these systems adapted to the conditions of a certain geographical location. The paper started with modeling of specific angles of photovoltaic panel and ends with a prototype of low concentrating photovoltaic system (LCPV). The simulation results show that the additional length decreases with the angle formed between the mirror and photovoltaic module x, and increases with the incidence angle h, meaning with the duration of the orientation step. Also, the concentration ratio increases with the increase of angle x. In order do not overweight the supporting structure of the LCPV system there have been utilized materials with light weight.

Keywords: photovoltaic (PV), tracking system, low concentrating photovoltaic, modelling, design, geometry

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #25, pp. 210-219

Title of the Paper: Configurable Converter for Performance Assessment of Cascaded Multilevel Power Converters

Authors: Luis David Pabon, Edison Andres Caicedo, Jorge Luis Diaz Rodriguez, Aldo Pardo Garcia

Abstract: This paper presents the development of a configurable converter, designed and built for the evaluation of several configurations of cascaded H-bridge multilevel power converter with single DC source and separate DC source sub-topologies. The converter can be configured in the symmetric and asymmetric topologies and the voltage levels range is limited by the four H-bridges hardware. The converter also can be set to obtain modulations from 3 levels and up to 81 levels. For configuring the converter a MATLAB® graphical user interface was developed in order to facilitate the topology changes and selects the number of voltage levels and switching angles. It also allows optimizing the modulations by switching angles through a genetic algorithm. The interface data are encoded and transmitted to a FPGA which controls the configurable multilevel converter.

Keywords: Power converter, Multilevel converter, PWM, FPGA, optimization, genetic algorithm

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #24, pp. 199-209

Title of the Paper: MPPT Control Design of PV Generator Supplied DC Motor-Pump System Based on ABC Algorithm

Authors: A. S. Oshaba, E. S. Ali, S. M. Abd Elazim

Abstract: A new Maximum Power Point Tracking ( MPPT) system has been proposed for PV-DC motor pump system by designing two PI controllers. The first one is used to reach MPPT by monitoring the voltage and current of the PV array and adjusting the duty cycle of the DC/ DC converter. The second PI controller is designed for speed control of DC series motor by setting the voltage fed to the DC series motor through another DC/DC converter. The proposed design problem of MPPT and speed controller is formulated as an optimization problem which is solved by Artificial Bee Colony (ABC) to search for optimal parameters of PI controllers. Simulation results have shown the validity of the proposed technique in delivering MPPT to DC series motor pump system under atmospheric conditions and tracking the reference speed of DC series motor. Moreover, the performance of the proposed ABC algorithm is compared with Genetic Algorithm (GA) for different disturbances to prove its robustness.

Keywords: Photovoltaic System, Optimization Algorithm, Maximum Power Point Tracking, PI Controller, Speed Control, DC Series Motor Pump System

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #23, pp. 190-198

Title of the Paper: Enhanced Conductivity and Ion Exchange Capacity of Chitosan Membranes through Modification with Lithium for Lithium Polymer Battery Application

Authors: S. N. Asnin, Wahab, D. Permana, L. O. Ahmad, S. H. Sabarwati, L. O. A. N. Ramadhan

Abstract: Modification of chitosan membranes using lithium has been developed. The chitosan membranes were prepared from several deacetylation degree of chitosan. The effect of the deacetylation degree towards an ion conductivity properties of the chitosan membranes, effect of concentration of chitosan-lithium membranes and capability of ionic conductivity as an electrolyte polymer for lithium polymer battery application were studied. The membranes were prepared by the solvent evaporation method. Fourier transform-infrared spectroscopy showed a peak at 1573.8 cm-1 correspond to the ionic interaction between lithium salt with NH2 groups from chitosan. The scanning electron microscopy analysis showed high pore density and rigidity of chitosan membrane microstructure, meanwhile chitosan-lithium membranes have clusters which indicated the deposition of lithium nitrate salt at chitosan polymer chains. The water uptake capacity of the chitosan-lithium membranes was higher than that of the chitosan membrane. The tensile strength analysis showed that the chitosan-lithium membranes was more elastic than the chitosan membranes. Chitosan membrane conductivity and ion exchange capacity are 1.70 x 10-2 and 2.11 meq.g-1, while the conductivity after adding lithium salt increased to 8.53 x 10-2 and 3.16 meq.g-1, respectively. The result indicated that modification of chitosan by the addition of lithium salt increased the membrane ionic conductivity and ion exchange capacity values. This solid polymer electrolyte membrane has a potential to be used as a polymer electrolyte in lithium battery.

Keywords: battery, chitosan, conductivity, deacetylation, exchange capacity, lithium, membrane

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #22, pp. 183-189

Title of the Paper: Injury and Throwing Distance in Teenage Cyclist-Vehicle Crash

Authors: Filippo Carollo, Vincenzo Naso, Gabriele Virzi’ Mariotti

Abstract: The study of the injury caused by vehicle-teenage cyclist crash is presented in this paper. The results of the crash with three vehicles: sedan, SUV and Pick up are compared. Three different positions are analyzed: front, rear and lateral position. The injury on the cyclist head is examined by HIC criterion, in the way indicated by the rules. A comparison is done between the results of the simulations for Pick up, SUV and sedan, concluding that the injury of the head is more dangerous for Pick-up impact than SUV or the sedan, but only at greater speed than 40 km/h. Teenage cyclist is more likely to suffer an injury to the chest in rear impacts with the sedan, because 3 ms values remain above the values obtained with the SUV and Pick up. Unlike Pick up could cause greater injury to the chest in the front and side impact because of greater height from the ground. The vehicle mass has not great importance, but only to low speed. Consideration is made that teenage cyclist has a better chance of surviving in the front impact collision than adult pedestrian, because HIC values remain consistently below the determined values. A further comparison is done between the impact points of the three vehicles concluding that both the shape of the bonnet and the height of the front part must be studied carefully in order to reduce the damage to cyclists and pedestrians. At last the throwing distance are calculated and compared with the literature data, concluding that they are strongly dependent on the relative position.

Keywords: teenage bicyclist, vehicle impact, (AIS4+) injury, HIC, 3ms, throwing distance, biomechanics

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #21, pp. 171-182

Title of the Paper: Analysis of Torque Capability and Limits of Operation of AC Traction Motors on Sustainable High-Speed Electric Trains

Authors: Cornelia A. Bulucea, Doru A. Nicola, Marc A. Rosen, Nikos E. Mastorakis, Carmen A. Bulucea

Abstract: The sustainability of electric railway vehicles is related both to high energy efficiency and to mitigated environmental impact during all life stages (namely, production, use and end-of-life). It is widely accepted that the environmental performance of traction motor operation is closely related to its energy conversion efficiency. In line with this idea, sustainable operation of electric traction motors on railway systems represents a significant goal nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric trains mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. An important issue that correlates these sustainability aspects is the electromagnetic torque developed by an electric traction motor, taking into consideration that the wide operating torque-speed range required to the electric railway vehicle imposes significant constraints on achieving a high efficiency of the traction motor. In order to provide an overview of the technical and environmental performance of the sustainable operation of electric trains, a detailed analysis is carried out of the electromagnetic torque capability of AC electric motors utilized as traction motors in modern locomotives of high power and/or high speed. The results of this work may help in enhancing the main criteria for optimising the high-efficiency operation of sustainable electric railway traction systems.

Keywords: Electric railway system, electromagnetic torque, exergy, electric high-speed train, induction motor, sustainability, synchronous motor

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #20, pp. 156-170

Title of the Paper: An Approach Towards Real Time Short Term Load Forecasting Using Grey Index Models for Smart Grid Framework

Authors: Sreenu Sreekumar, Jatin Verma, Sujil A., Rajesh Kumar

Abstract: Short term load forecasting (STLF), which aims to predict system load over an interval of one day or one week, plays a crucial role in the control and scheduling operations of a power system. Most existing techniques on short term load forecasting try to improve the performance by selecting different prediction models. However, the performance also rely heavily on the quality of training data. Although the grey forecasting model has been successfully adopted in various fields and has demonstrated promising results. This paper proposes three short term load forecasting models based on Grey System theory, namely Grey One Index Model (GM(1,1)), Grey Two Index Model using previous year similar day values as input along with previous hour values (GMY (1,2)) and Grey Two Index Model using previous day values as input along with previous hour values (GMD (1,2)) respectively. As shown in the results, the Grey model and its optimized models can increase the existing prediction accuracy. These models have a potential to be used for real time forecasting in smart grid network due to their negligible processing time.

Keywords: Short Term Load Forecasting, Grey One Index Model, Grey Two Index Model

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #19, pp. 147-155

Title of the Paper: To Reduce Impact of the Variation of Power from Renewable Energy by Using Super Capacitor in Smart Grid

Authors: Amam Hossain Bagdadee

Abstract: In the production of renewable energy, maximum power point tracking (MPPT) is always expected .The amount of regeneration energy sources in the network integration of infinite energy, mainly due to changes in the flow of energy. From these sources, in order to ensure the quality of power, in the case of cable resistance, and striking which can be applied mainly AC voltage from high-quality, energy storage, and a significant level to inject energy. On the other hand, this is not a useful resolution. In this article, the energy storage super capacitors have been proposed to be used as the main power source to obtain the time needed to support demand management to work properly (the energy, as the infrastructure, installation via ICT). As a result, it is possible sources.

Keywords: Connection and control of the production of renewable energy, converter DC-DC, integrated system, Super Capacitor

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #18, pp. 139-146

Title of the Paper: Wavelet Based Multi-Terminal Transmission Line Protection with MicroGrid

Authors: S. Chandra Shekar, G. Ravi Kumar, S. V. N. L. Lalitha

Abstract: This paper introduces a novel protection scheme for protecting multi-terminal transmission system combined with microgrid comprises of wind, solar, fuel cell energy sources.Microgrids provide clear economic and environmental benefits for end-customers, utilities and society. However, their implementation poses great technical challenges, such as a protection of microgrid and transmission system. Protection must respond to both utility grid and microgrid faults. The major challenges are a protection system for microgrid which must respond to main grid as well as microgrid faults. After the microgrid is model is developed and it is connected to an equivalent multi terminal transmission system. Wavelet Multi Resolution Analysis is used for detection, classification and location of faults on multi terminal transmission system as well as microgrid resources.The proposed algorithm is tested and it is proved for the detection, classification of faults on transmission system with microgrid which is almost independent of fault impedance, fault inception angle and fault distance of feeder line.

Keywords: Microgrid protection, inverter-interfaced microgrids, islanded microgrid

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #17, pp. 133-138

Title of the Paper: The Role of PSO Meter Placement in Distribution State Estimation

Authors: L. Ramesh

Abstract: Optimal meter placement with state estimation plays a major role in monitoring and controlling of Distribution System. The objective of this work is to optimize the number of necessary measurements and Remote Terminal Units, subject to the constraints of the system observability requirements for best voltage estimation. A global optimization algorithm and Particle Swam Optimization is proposed to fulfil the requirement. The parameter values are estimated using the Hybrid Artificial Neural Network based state estimation technique of injecting pseudo measurements at un-metered buses. The algorithm is simulated for IEEE and Indian standard bus distribution systems and the results are presented. The effectiveness and flexibility of PSO are demonstrated by validating the results with Mathematical techniques and the effectiveness of estimator.

Keywords: Branch and Bound technique, Meter Placement, Particle Swarm Optimization, Power Distribution Systems, State Estimation

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #16, pp. 125-132

Title of the Paper: Optimization of droop setting using Genetic Algorithm for Speedtronic Governor controlled Heavy Duty Gas Turbine Power Plants

Authors: M. Mohamed Iqbal, R. Joseph Xavier, J. Kanakaraj

Abstract: Biomass is identified as one of the major renewable energy sources for electrical power generation. Heavy duty gas turbine engines are preferred for clean and efficient power generation. An extensive literature survey reveals that the governor droop setting of the heavy duty gas turbines varies from 2 percentage to 10 percentage. But it needs to be optimized for analyzing the dynamic response of heavy duty gas turbine plants in grid connected operation. An attempt has been made in this paper to optimize the speedtronic governor droop setting of all heavy duty gas turbine plants ranging from 18.2MW to 102.6MW using genetic algorithm. Step response of all heavy duty gas turbine plants with the genetic algorithm based droop setting are obtained using MATLAB/Simulink. On comparing the simulation results based on all time domain specifications and performance index criteria, it is witnessed that the genetic algorithm based droop setting yield optimal transient and steady state responses than the previous findings using SYSTAT software. Therefore the genetic algorithm based droop setting is identified as the optimal droop setting for all heavy duty gas turbine plants in grid connected operation.

Keywords: Biomass Power, Heavy Duty Gas turbine, Optimal droop setting, Genetic Algorithm, Simple cycle operation, Simplified Model, Single shaft turbine, Speedtronic Governor, SYSTAT

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #15, pp. 117-124

Title of the Paper: Hybrid Distributed State Estimation Algorithm with Synchronized Phasor Measurements

Authors: Camilo A. Villarreal, Jorge W. González, Gabriel J. Lopez, Idi A. Isaac, Hugo A. Cardona

Abstract: This paper proposes a hybrid distributed state estimation algorithm with synchronized phasor measurements. The implementation is easy since it initially uses a conventional or traditional state estimation and then adds a non-iterative second linear step calculation, which can be implemented by software without hardware investments. Distributed algorithm accuracy was verified in a well-known power system. Even though it was a little less than the state estimation made to the complete system, it offers a faster computation. Hence, for applications that require real-time awareness of the power system, the distributed scheme results are a great alternative that can significantly reduce the bandwidth requirements, like time delays in the processes involved in the supervision and control of the power system. The proposed algorithm makes use of a central coordinator and assumes that each area of the system has at least one synchronized phasor measurement that allows finding the synchronization angles with respect to the angular reference of the system.

Keywords: State Estimation, Distributed State Estimation, Hybrid State Estimation, PMU, SCADA, Synchronized Phasor Measurements

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #14, pp. 111-116

Title of the Paper: Evolutionary Optimization Algorithms in Designing a UPFC Based POD Controller

Authors: Anwar Haider, Ali Al-Mawsawi, Ahmed Al-Qallaf

Abstract: This paper investigates the design of a unified power flow controller (UPFC) based power oscillations damping (POD) controller using evolutionary optimization algorithms (EA). It introduces two optimization algorithms: biogeography based optimization (BBO) and particle swarm optimization (PSO), that are used to design the POD controllers. The optimal set of parameters for the controllers are found using two different objective functions, eigenvalue based objective function and time based objective function, over a wide range of system operating points in order to obtain a robust controller. The obtained controllers are then verified and tested over four different loading conditions of the system with different system parameter uncertainties introduced in each case.

Keywords: Power system oscillations, unified power flow controller, biogeography based optimization, particle swarm optimization, evolutionary optimization algorithms, FACTS

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #13, pp. 100-110

Title of the Paper: Hybrid Carrier PWM Strategies for Three Phase H-Bridge Multilevel Inverter

Authors: C. R. Balamurugan, S. P. Natarajan, R. Bensraj, T. S. Anandhi

Abstract: In this paper, hybrid modulation methods suitable for H-bridge MLI is discussed. The results of experimental work using dSPACE system only are presented for three phase five level cascaded type inverter. Different hybrid carrier PWM (Pulse Width Modulation) strategies using sinusoidal reference, third harmonic injection reference, 60 degree reference and stepped wave reference for the chosen inverter are initially developed using SIMULINK. Strategies developed are then implemented in real time using dSPACE/RTI. The five level output voltages of the chosen MLI (Multi Level Inverter) obtained using the dSPACE system based PWM strategies and the corresponding % THD (Total Harmonic Distortion) and VRMS (fundamental) are presented and analyzed. It is seen that PS+VF (Phase shift+ Variable Frequency) and PS+PD (Phase Disposition) for sinusoidal reference. PS+VF and CO+PS for THI (Third Harmonic Injection) reference, PD+VF for 60 degree reference and APOD+PD and PD+VF for stepped wave provides output with relatively low distortion. It is found that CO+PD with sine reference, APOD+CO and CO+PS PWM with THI reference, CO+PD PWM with 60 degree reference and APOD+CO and CO+PD PWM with stepped wave reference perform better since it provides relatively higher fundamental RMS output voltage and relatively lower stress on the devices. The simulation and hardware results closely match with each other.

Keywords: Hybrid, THD, DSPACE, RTI, Control desk, PWM, Driver circuit

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #12, pp. 90-99

Title of the Paper: Congestion Management Using Multi-Objective Grenade Explosion Method

Authors: S. Surender Reddy

Abstract: The operational aspects of power systems pose some of the most challenging problems encountered in the restructuring of electric power industry. This paper focuses on Congestion Management within an Optimal Power Flow (OPF) framework in the deregulated electricity market scenario. The conventional OPF problem is modified to create a mechanism that enables the market players to compete and trade, and simultaneously ensures that the system operation stays within the security constraints. The centralized/pool and bilateral dispatch functions of an Independent System Operator (ISO) are considered in this paper. Here, Multi-Objective Grenade Explosion Method (MO-GEM) based approach is presented to formulate as multi-objective optimization problem with competing fuel cost and system loss minimization as objective functions. The proposed approach is tested on IEEE 30 bus system. The simulation results revealed the capabilities of the proposed MO-GEM approach to generate well distributed Pareto optimal non-dominated solutions of multi-objective generation cost and transmission loss minimization.

Keywords: Congestion Management, Optimal Power Flow, Electricity Markets, Evolutionary Algorithms

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #11, pp. 81-89

Title of the Paper: Sensorless Fuzzy Sliding Mode Speed Controller for Induction Motor with DTC Based on Artificial Neural Networks

Authors: Sarra Massoum, Abdelkader Meroufel, Abderrahim Bentaallah, Fatima Zohra Belaimeche, Ahmed Massoum

Abstract: The objective of this work is to develop a Fuzzy Sliding Mode Speed Controller and to replace the conventional selector switches of the voltage inverter by a selector based on Artificial Neural Networks (ANNs) for the induction motor drive. The Direct Torque Control (DTC) is known to produce quick and robust response in AC drive system. However, during steady state, torque, flux and current ripple occurs. An improvement of electric drive system can be obtained using a DTC method based on ANNs which reduces the torque and flux ripples. The rotor speed and stator flux are estimated by the model reference adaptive system (MRAS) scheme which is determined from measured terminal voltages and currents. The speed loop is carried out by a Fuzzy Sliding Mode Controller (FSMC) giving high performance and robustness to the drive system. The MATLAB SIMULINK is used to perform the simulation. The simulated results of this method are discussed and compared with conventional DTC.

Keywords: DTC, induction motor, MRAS, speed FSMC, ANNs, torque ripple minimization

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #10, pp. 72-80

Title of the Paper: Economic Analysis of Energy Storage System Integration with a Grid Connected Intermittent Power Plant, for Power Quality Purposes

Authors: Alejandro Nieto, Vasiliki Vita, Lambros Ekonomou, Nikos E. Mastorakis

Abstract: The increasing integration of grid scale intermittent power plants, like wind farms, is impacting negatively the stability of the interconnected power grid affecting the load factor of the intermittent power plant. Energy storage systems (ESS) are being considered as a potential solution for this problem since it can increase the power being exported to the grid by the wind farm, making it more stable, and therefore guarantying its economic feasibility. In this paper an economic study is carried out to analyze the economic feasibility for the integration of flywheel energy storage systems (FESS) with a wind power plant. It was concluded that the installation of the FESS is only feasible with the government subsidy in renewable energy projects, if considering that installation costs would not be reduced more than 10% of the estimated value. In addition, the integration of ESS would potentially improve the load factor of the power plant by increasing the load factor and therefore, make the project more profitable from an independent power producer perspective.

Keywords: Energy Storage Systems, Economic Study, Renewable Energy

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #9, pp. 65-71

Title of the Paper: Harmonic Assessment in Jordanian Power Grid Based on Load Type Classification

Authors: Eyad Almaita

Abstract: The demand of efficient power converters lead to the proliferation of nonlinear loads in the power system. These nonlinear loads cause a serious problems that affect the power quality in both transmission and distribution systems. One of the major Power quality problems is Harmonic pollution. Understanding and quantifying the harmonics level in electrical power grid are crucial before proposing any successful method for mitigating harmonics problems in the grid. In this paper, the harmonics level in Jordan Low-Voltage Electrical Power Grid (JLVEPG) is investigated. The loads are divided into five categories: : (i) industrial loads, (ii) commercial loads, (iii) hospital loads, (iv) residential loads, and (v) office loads. Assuming each category will inject similar harmonics in the grid, which will facilitate harmonic assessment in the power system. Also, this categorization of the loads will make proposing harmonic mitigation solutions much easier. A field measurement for the major electrical units (Voltages, currents, and power) in JLVEPG is carried out for different locations in multiple cities. These measurements are followed by data analysis techniques in order to identify the total harmonic distortion (THD), the most dominant harmonic in each load category, and the harmonic power as a ratio to the active power.

Keywords: Power quality, harmonics, distortion, harmonic assessment, Jordan, THD

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #8, pp. 58-64

Title of the Paper: Research on the Numerical Accuracy of Equipotential Ground Model Based on Method of Moment

Authors: Junyang Ma, Zaijun Wu, Minqiang Hu, Xiaobo Dou, Yurong Wang, Hao Chen

Abstract: In numerical calculations of grounding grid based on the method of moment, accurately calculation of the resistance matrix is an important step. The direct numerical integration method, Heppe’s method and Kouteynikoff’s method have the most broad influence in the previous publications, and the accuracy of these algorithms require further evaluation. A software for simulating grounding systems has been developed based on the method of moments in this paper, it implements the above several important algorithms. Under the assumption of uniform soil and ignoring the conductor impedance, the calculation results of the above methods and CDEGS are compared, and sources of error are analyzed. Furthermore, since the grounding electrode need to be cut into small segments properly when using the method of moment, the effect of the conductor’s different divisions for accuracy is analyzed quantitatively, and the rule of the calculation accuracy of grounding resistance with the change of segment numbers is obtained. After comparison of the above methods in the case study, theoretical analysis and program test reveal the theoretical flaw of the Kouteynikoff's method.

Keywords: Grounding grid, numerical calculation, method of moment, Hepe’s method, Kouteynikoff’s method, CDEGS, Numerical Accuracy

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #7, pp. 52-57

Title of the Paper: Forecasting Electricity Price Using Seasonal Arima Model and Implementing RTP Based Tariff in Smart Grid

Authors: Hemant Joshi, Vivek Pandya, Chetna Bhavsar, Mitesh Shah

Abstract: A Smart Grid has a two-way digital communication system and it encourages customers to actively participate in different types of Demand Response (DR) programs. In the Smart Grid market, both the supplier and broker agent earn profit while distributing the electrical energy. They have to balance the supply and demand during the distribution of energy. They also participate in energy trading to earn more money. To minimize trading risks, forecasting of wholesale electricity prices is necessary. A Real Time Price (RTP) based power scheduling scheme can be implemented effectively in Smart Grid to match supply and demand. In this scheme, Home Energy Controllers (HEC) and Smart Plugs can be used to shift the operation of schedulable load from peak period to off-peak period. To shift the operation of schedulable load during off-peak period, electricity price should be available in advance. In order to have the electricity price in advance, accurate forecasting is needed. Demand and supply depends on so many factors such as weather condition, cloud cover, wind speed, day of the week and festivals. It is difficult to forecast energy prices in such uncertainty. In this work, the best fitted seasonal ARIMA (Auto Regressive Integrated Moving Average) model is identified and used to forecast the next week’s electricity price. This forecasted electricity price helps in deciding the next day’s load pattern and minimizing the trading risk. Algorithms for HEC and Smart Plug are presented in this work to identify the optimized time slots and to allow power to the schedulable appliances during those slots.

Keywords: Smart Grid, Demand Response, Real Time Price, Smart Plug, Home Energy Controller, ARIMA

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #6, pp. 43-51

Title of the Paper: A Development of Acoustic Energy Transfer System through Air Medium Using Push-Pull Power Converter

Authors: Thoriq Zaid, Shakir Saat, Norezmi Jamal, Siti Huzaimah Husin, Yusmarnita Yusof, S. K. Nguang

Abstract: This paper presents a development of Acoustic energy transfer (AET) system through air medium using push-pull power converter. The push-pull converter may operate under zero voltage switching condition at resonance frequency and capable to minimize switching losses. This paper investigates the performance of AET through the air by using ceramic disc ultrasonic transducer, specifically for low power applications. A multiple input-output transducer is also designed in this paper. The simulation and experimental works are carried out and the obtained results are analysed accordingly. Based on the experimental results, the 1.07mW output power is obtained at 40kHz operating frequency. The multiple transceiver design offers 100% efficiency of energy transmission which is 7.24mW output power.

Keywords: Contactless Energy Transfer, Acoustic energy transfer, Ultrasonic transducer, Push-pull converter

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #5, pp. 35-42

Title of the Paper: Comparative Evaluation of New FLC Controller Based MPPT for a DC to DC Buck-Boost Zeta Converter

Authors: R. Arulmurugan, N. Suthanthiravanitha

Abstract: A new intelligent technique of tracing the peak power point of a standalone photovoltaic (PV) module using Fuzzy Logic Control (FLC) is presented in this paper which exploits the effects of the characteristic of PV module. Partial shaded and change in weather conditions produces numerous local maximum peak points (MPP), which makes the tracing of the multiple global peak power a challenging task. Furthermost of traditional tracing technique fail to operate correctly under these non-uniform irradiance situations. The real traditional FLC search based maximum power point tracking (MPPT) flops to trace the peak power under partial shaded situations. This paper advances the technique by considering the wide range of search and power ripple so that the designed FLC technique traces maximum power for all the situations. It is tested for dissimilar weather condition through Matlab simulation and verified laboratory experimentally. In this paper, the merits of using a novel FLC is also offered. Three inputs and single output fuzzy rules are developed. From the Matlab simulation outcomes, it is observed that the FLC controlling technique decreases error and it provides rapid reaction to environmentally friendly variations. The competence of the designed technique has closely coordinated with the true maximum power point (MPP) and the successful laboratory experimental results attained with a 100 Watt photovoltaic module specify that the method can be favourably realized for photovoltaic standalone system.

Keywords: Maximum Tracking, Photovoltaic, Fuzzy Logic Control, DC to DC buck-boost Zeta converter

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #4, pp. 27-34

Title of the Paper: Optimal Power Flow Using Cuckoo Search Considering Voltage Stability

Authors: M. A. Elhameed, Mahmoud M. Elkholy

Abstract: Optimal power flow is the most complicated economical problem in power system operation. This is due to the nonlinearity of load flow equations and constraints on voltage, thermal limits and angle and voltage stability. The objective of this problem is to distribute system loads among generators with minimum cost while achieving all equality and inequality constraints. Nowadays, meta heuristic methods are used to solve this problem such as genetic algorithm, particle swarm and tabu search. In this paper Cuckoo search is investigated with additional constraints on voltage stability and output of reactive power compensators. Considering the initial load angles of generators will enhance the transient stability of power system. Results obtained by Cuckoo search are compared to that obtained by genetic algorithm, Tabu search and gradient descent methods. With the same loading conditions and constraints, Cuckoo search based optimal power flow gives less cost compared to these methods. The algorithm is investigated on IEEE 30 bus system.

Keywords: OPF, Cuckoo search, voltage stability, reactive power compensators

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #3, pp. 18-26

Title of the Paper: Power Transformer Fault Detection and Isolation Based on Intuitionistic Fuzzy System

Authors: Manikandan Pandiyan, Geetha Mani

Abstract: Power transformer oil using Dissolved Gas Analysis (DGA) is the most used diagnosis method for power transformer faults. Though various methods have been developed to interpret DGA results, sometimes they fail to determine the faults. Forecasting of the ratios of key-gas in transformer oil is a complicated problem due to its non-linearity and the small amount of training data. This paper presents Intuitionistic Fuzzy System (IFS) to diagnose several faults in a transformer. This proposed approach is recommended for fault transformer diagnosis and the suitable actions to be taken. It has been proved to be a very advantageous tool for transformer diagnosis and upkeep planning. This method is applied to an independent data of different power transformers and various case studies of historic trends of transformer units. This method has been successfully used to identify the type of fault developing within a transformer even if there is conflict in the results of AI technique applied to DGA data.

Keywords: Power transformer, DGA, IFS, fault diagnosis

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 10, 2015, Art. #2, pp. 10-17

Title of the Paper: Renewable Energy Impact on Power Quality Performances in Modern Electric Grids

Authors: Morris Brenna, Federica Foiadelli, Michela Longo, Dario Zaninelli

Abstract: The significant increase of the Renewable Energy Sources (RES) has radically transformed the electricity generation system presenting many aspects to be studied and analyzed. RESs such as solar and wind are fluctuating and weather-driven sources, that can introduce consequences for the functioning and the quality of the delivered power to the end users. This paper aims to present a deep research of the impact, in terms of power quality, of the introduction of photovoltaic and wind generation into the Italian electric grid, that covers many different case studies since the variety of its topology depending on the geographical regions. A deep study, based on infield measurements data, of the correlation between power quality, in particular voltage sags, and renewable energy introduction is presented and discussed.

Keywords: Power Quality, Voltage Sags, Wind Farm, Photovoltaic System, Renewable Energy

WSEAS Transactions on Power Systems, ISSN / E-ISSN: 1790-5060 / 2224-350X, Volume 11, 2016, Art. #1, pp. 1-9